The subject matter disclosed herein relates to gas turbine engines.
Gas turbine engines are used in a wide variety of applications, such as power generation, aircraft, and various machinery. Gas turbine engines generally combust a fuel with an oxidant (e.g., air) in a combustor section to generate hot combustion products, which then drive one or more turbine stages of a turbine section. The turbine stages, when driven by the hot combustion products, transfer rotational power to a shaft. The rotating shaft, in turn, drives one or more compressor stages of a compressor section to compress oxidant for intake into the combustor section, and can also drive an electrical generator to produce electrical energy.
In certain instances, the electrical energy supplied by the electrical generator may be fed into an electrical grid, such as an electrical grid of a municipality. The gas turbine may be configured to adjust its operation in response to changes in the municipality's electrical grid. For example, if the electrical grid slows, the gas turbine might increase its output of electrical energy to maintain the amount of electrical power available to the municipality. Increasing the amount of combustion in the gas turbine engine, which increases the speed of the shaft that drives the electrical generator, may enable such an increase in the electrical output.
As the combustion parameters change, such as the rate of combustion in the combustor section, the nature of the combustion products, such as the relative levels of particular gases in the combustion products (e.g., nitrogen oxide (NOx), carbon dioxide (CO2), and oxygen (O2)) can be affected. Unfortunately, certain ratios can lead to excessive levels of oxygen in the combustion products, which can be detrimental to the gas turbine system and downstream components. Furthermore, because the gas turbine engine system may include or be a part of other systems that operate as a result of the combustion process, the operation of these systems may also be affected, which can lead to process instabilities.